Day of the Week Calculator

Pick a date and the tool names its weekday. It opens on 1 January 2000, which was a Saturday. A few more results:

Typical uses are checking a weekday printed on an invitation or a contract, planning around a date next year, or finding the day you were born. Once the page has loaded, the weekday name appears in your device's language.

A common year has 365 days, which is 52 weeks plus one day. So the same date moves forward one weekday each year, and two when a 29 February falls in between. Christmas Day shows the pattern:

• 2026: Friday
• 2027: Saturday (one step)
• 2028: Monday (two steps, because 29 February 2028 comes first)
• 2029: Tuesday

This is a handy way to sanity-check a date someone gives you. If a document says "Friday 25 December 2027", one step from 2026 says that date is a Saturday, so something is wrong.

For dates in January and February, look at the leap day of the starting year instead, since it falls after your date. 1 January 2028 is a Saturday and 1 January 2029 is a Monday, two steps, because 29 February 2028 sits between them.

Two years have identical calendars when they start on the same weekday and are both leap years or both common years. 2026 starts on a Thursday and isn't a leap year, so its calendar is the same as 2015's and 2037's. Monday 19 October 2026 was also a Monday in 2015 and will be again in 2037.

That is useful if you have an old printed calendar or planner, and for spotting recurring dates. In 2026 the 13th is a Friday three times: in February, March and November.

The tool applies today's Gregorian calendar to every year, including years before any country used it. Historians call this the proleptic Gregorian calendar. For modern dates it makes no difference.

For old records it can. Many historical documents give dates in the earlier Julian calendar. A Julian date and the same Gregorian date are different days, so typing a Julian date in here returns the weekday of the wrong day. If you are checking a date from an old letter or a parish register, find out which calendar the writer used before trusting the weekday here.